All of the following statements about influenza virus structure and genome organization are correct EXCEPT:

## Influenza Virus Genome Organization **Key Point:** Influenza viruses possess a **segmented, single-stranded (negative-sense) RNA genome**, NOT double-stranded RNA. This is a critical distinguishing feature. ### Correct Structural Features | Feature | Details | |---------|----------| | **Envelope glycoproteins** | HA (hemagglutinin) — binds sialic acid receptors; NA (neuraminidase) — cleaves sialic acid | | **Genome type** | 8 segments of **single-stranded negative-sense RNA** | | **M2 protein** | Ion channel; target of adamantanes (amantadine, rimantadine) | | **Nucleoprotein (NP)** | Binds RNA segments to form RNPs; involved in viral replication | | **Polymerase complex** | PB1, PB2, PA proteins; catalyze transcription and replication | **High-Yield:** The segmented genome (8 segments) allows for **reassortment** when two different influenza viruses co-infect the same cell—this is the mechanism of **antigenic shift**, which generates pandemic strains. ### Why the Distractor is Wrong Double-stranded RNA (dsRNA) is found in **Reovirus** and **Rotavirus**, NOT influenza. Influenza's single-stranded negative-sense genome requires viral RNA-dependent RNA polymerase (RdRp) for transcription and replication. **Mnemonic:** **SSNRV** = Single-Stranded Negative-sense RNA Virus (Influenza, Measles, Rabies, Ebola). [cite:Harrison 21e Ch 195]